What is the diagnosis for a 76-year-old male with a history of Benign Prostatic Hyperplasia (BPH) taking tamsulosin (generic name: tamsulosin), presenting with urinary urgency, weak urinary stream, fever, nocturia, and urinalysis showing leukocyturia (trace of leukocytes), negative for nitrites, negative for hematuria, and presence of kidney stones (keystones)?

Differential Diagnosis for 76-year-old Male with Urinary Symptoms

Single Most Likely Diagnosis

• Urinary Tract Infection (UTI): The patient's symptoms of urinary urgency, weak stream, fever, and frequency, along with the presence of leukocytes in the urinalysis, suggest a UTI. Although the urinalysis is not strongly positive, the clinical presentation is consistent with a UTI, especially in an elderly male with a history of BPH.

Other Likely Diagnoses

• Prostatitis: Given the patient's history of BPH and symptoms of urinary urgency and frequency, prostatitis is a possible diagnosis. The presence of fever also supports this diagnosis.
• BPH Exacerbation: The patient's symptoms of weak stream and urinary frequency could be due to an exacerbation of his existing BPH, possibly triggered by a UTI or other factors.
• Overactive Bladder: The patient's symptoms of urinary urgency and frequency could also be consistent with overactive bladder, although this would not explain the fever.

Do Not Miss Diagnoses

• Sepsis: Although the patient's symptoms are largely localized to the urinary tract, the presence of fever and potential UTI raises the concern for sepsis, especially in an elderly patient. Sepsis is a life-threatening condition that requires prompt recognition and treatment.
• Kidney Stones with Infection: The presence of "keystones" (likely a typo for kidney stones) in the urinalysis, although only a trace, raises the concern for a kidney stone with associated infection, which could be a serious condition.
• Prostate Cancer: Although less likely, prostate cancer could present with urinary symptoms similar to BPH, and it is essential to consider this diagnosis in an elderly male, especially if his symptoms do not respond to treatment for BPH or UTI.

Rare Diagnoses

• Interstitial Cystitis: This is a chronic condition characterized by bladder pressure, bladder pain, and sometimes pelvic pain. The symptoms can be similar to those of a UTI, but the urinalysis would typically be negative.
• Tuberculosis of the Urinary Tract: This is a rare condition that could present with similar symptoms to a UTI, including fever and urinary frequency. However, it would be unusual in this clinical context without other systemic symptoms or risk factors.